The study, published in Frontiers in Nutrition, was led by the Centre for Nutraceuticals at the University of Westminster and put an interesting theory to the test – do you run faster when using with a pink-coloured drink, as opposed to a translucent drink?
Participants were asked to run on a treadmill for 30 minutes at a constant RPE (rate of perceived exertion). Throughout this time, runners rinsed their mouths with either a pink or a clear drink. The two drinks had exactly the same constituents, being made with water and low-calorie artificial sweetener. The only difference being that the pink drink was coloured with a tasteless pink food dye and the other was not.
Why the pink?
Researches chose to dye the drink pink as they found that the colour is psychologically associated with perceived sweetness, hence athletes expect to be consuming carbohydrates. Another theory was also tested within the study; the drinks were used to ‘rinse’ the mouth rather than consumed as normal. This is because mouth rising with carbohydrate drinks during exercise has previously been shown to reduce perceived exertion.
The placebo effect
The placebo effect refers to the positive psychosomatic effects on one’s health from taking a substance that a participant in a study believes will help them feel better, this is due to a belief in the treatment and subsequent expectation of improved health, rather than the substance itself actually containing any beneficial ingredients.
Hence, the core of the experiment was founded on the strength of the placebo effect caused by mouth rinsing with a drink that visually looked like it contained performance-aiding carbohydrates.
What were the results?
Results show that not only did those given the pink drink run an average 121 metres further and had a mean speed increase of 4.4%, they also claimed to find the exercise more enjoyable overall. Though further research is needed on this placebo effect in terms of influence on reward areas of the brain, the initial results are already causing a buzz in the sports performance world.
Dr Sanjoy Deb, corresponding author on the published paper, said of the study: “The influence of colour on athletic performance has received interest previously, from its effect on a sportsperson’s kit to its impact on testosterone and muscular power. Similarly, the role of colour in gastronomy has received widespread interest, with research published on how visual cues or colour can affect subsequent flavour perception when eating and drinking.
“The findings from our study combine the art of gastronomy with performance nutrition, as adding a pink colourant to an artificially sweetened solution not only enhanced the perception of sweetness, but also enhanced feelings of pleasure, self-selected running speed and distance covered during a run.”
Daniel R. Brown, Francesca Cappozzo, Dakota De Roeck, Mohammed Gulrez Zariwala, Sanjoy K. Deb. Mouth Rinsing With a Pink Non-caloric, Artificially-Sweetened Solution Improves Self-Paced Running Performance and Feelings of Pleasure in Habitually Active Individuals. Frontiers in Nutrition, 2021; 8 DOI: 10.3389/fnut.2021.678105
Image Credit: Getty Images